Flights in and out of Queenstown Airport have been disrupted today due to ice on the runway in a "never seen before" snap freeze.
Chief executive of Queenstown Airport Scott Paterson said half a dozen flights were affected by ice this morning and this caused some delays.
Black ice also forced the closure of the Kawarau Gorge road (State Highway 6) between Queenstown and Cromwell, the road finally reopening around midday.
Mr Paterson said while all international flights were running to schedule, other flights had to be diverted in the morning.
The runway was now clear of ice and flights had recommenced, Mr Paterson said.
However, a flight from Queenstown to Christchurch and one from Christchurch to Queenstown were cancelled this afternoon.
Detailed runway inspections were carried out throughout the winter, Mr Paterson said.
"The feedback we had from the rescue fire guys who do this inspection work was they have never seen anything like this before.
"We basically had rain first up, the rain stopped and then suddenly Queenstown was snap frozen. All that water on the runway and the roads just turned to ice."
Black ice warning on roads
Motorists across the South are warned of severe black ice on many roads in the area.
Light drizzle fell and froze on several Central Otago roads, making conditions extremely dangerous, police said, including the many roads in the Omarama-Ohau area.
With the opening of the Ohau Ski Field tomorrow morning police have urged people to exercise extreme caution.
There had been "numerous" crashes due to the ice, Southern police communications Sergeant Mark Booth said earlier today.
State Highway 93 was closed at Clinton for much of the morning following a crash, one of two in the South Otago/Southland area.
Ice also prompted the New Zealand Transport Agency to issue cautions for SH6 Wanaka-Haast, SH94 Mossburn-Te Anau and SH8 the Lindis Pass.
- Check highway conditions here
Danseys Pass road, in the Maniototo, remains closed owing to snow.
Meanwhile, North Island motorists are being urged to take care while driving near Rotorua this morning as black ice plagues the area.
Northern police communications Inspector Chris Tate said there was black ice on State Highway 5, and Dansey Rd.
"There is a lot of ice around, so people need to be careful."
- additional reporting Mountain Scene
